A display device generally used comprises a cathode ray tube (CRT), a liquid crystal display (LCD) device using an electric field and optical effect, a plasma display panel (PDP) using gas discharge, and electro luminescence display (ELD) using an electric filed light emitting effect. Among them, studies for an LCD device is under active development.
The LCD device is used for a monitor of a laptop computer, a monitor of a desktop computer, and a large scale information display device.
Since the LCD device is a device of a light receiving characteristic displaying an image by controlling an amount of light illuminated to an LCD panel, it illuminates light onto the LCD panel using a backlight unit.